Pocket of air found where man's brain should've been

An 84-year-old man in Ireland in otherwise good health went to the emergency room with alarming symptoms — and doctors were stunned to find that he was missing the right frontal lobe of his brain.

The man sought medical attention after several months of unsteady walking, multiple falls and weakness on his left side. He didn’t smoke, barely drank alcohol and had a solid medical history, according to a report published in BMJ Case Reports.

“There was no confusion, facial weakness, visual or speech disturbance,” the doctors wrote. “He was otherwise fit and well, independent with physical activities of daily living … and lived at home with his wife and two sons.”

But a head CT and MRI scan revealed that where the right frontal lobe of his brain should be, the patient had only a large, empty void, called pneumocephalus. The condition is when a pocket of pressurized air forms within the cranium, which typically happens after brain surgery, the study’s authors said. In this man’s case, the air cavity measured 3.5 inches at its longest point — an enormous size.

“In my research for writing the case report I wasn’t able to find very many documented cases of a similar nature to this one,” Finlay Brown, a physician on the case, told the Washington Post.

The pneumocephalus, in this case, was caused by an osteoma, a benign bone tumor, that formed in the patient’s sinuses and eroded through the base of his skull.

“From speaking to the specialists, it seems it has been progressing insidiously over months to years,” Brown said. “When the patient sniffed/sneezed/coughed he would most likely be pushing small amounts of air into his head.”

His left-sided weakness was likely caused by a small stroke — a “rare” side effect of having an air cavity in the brain. To revert it, the man had two surgeries: one to decompress the air pocket and another to remove the offending tumor. He was prescribed medication to prevent another stroke and instructions to monitor the feeling in his left side and after 12 weeks, he “remained well,” according to the study.

Brown and his coauthors, however, stressed in their paper that symptoms like this patient’s should always be thoroughly explored.

“Because every now and then,” Brown told LiveScience, “there will be a rare (or) unknown causation of these that could be overlooked.”